48630

Parameters for nitric acid passivation of piping by circulation [India] 

April 28, 2008

I have been working with pharmaceutical equipments manufacturer for last couple of years. We manufacture WFI and RO plants and we do passivation of pipings internal product contact surface by circulation nitirc acid in pipings. But I dont know what should be the concentration of nitic acid solution, temperature of solution and what should be acid circulation time to achieve right passivation results.

I would be gratefull if some one can answer my question.

Manoj Jangid
Water management solution company employee - Ahmedabad, Gujarat, India

Manoj,
The best references, as alway, are the industry specifications. In this case ASTM A-967 [link is to spec at TechStreet]. You can also use a copy of the now defunct mil spec QQ-P-35 [link is to spec at TechStreet]c, as the nitric procedures listed within remain largely unchanged in the specs that replaced it.

You may also chose to passivate your pipe systems with a citric acid based formulation. Let us know if we can help.

Ray Kremer Stellar Solutions, Inc. Algonquin, IL, USA